Blender constraint, parent issue
thank you so much for the answers. Meanwhile I was able to come up with another solution,
but still thank you for the responses.

My solution was following.


Create your base node
Create an object which should move to the center of the base node
Create a line curve, for example Vector X+ (1,0,0), I used a small phython addon for that
Use a locked track constraint on the object and as source the line curve. Direction should be X
Assign the object as a child of the line
Now you select the line &amp; object and create a duplicate, rotated by the Z axis. I used 3 objects so it was 120° 
Delete the constraints of both objects, and create a new constraint copy location of the first created object. Use the local coordinate system on both values.
Assign all moveable objects as child nodes of the base node.


Now it should work as expected. You can lock the obejcts position and only X should be active in the main moveable object.

I added an arrow to limit the X axis movement and use this as a copy location source for the main moveable object.

Thank you again for the responses. Really appreciated!

Max